JP2011222451A - Thermoplastic resin composition for coating electric wire having heat deteriorating resistance improved - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic polyester resin composition for coating electric wires that comprises extrudability, heat deteriorating resistance and abrasion resistance.SOLUTION: The thermoplastic polyester resin composition for coating electric wires contains, on (A) 100 pts.wt. of thermoplastic polyester resin (A component) having a terminal carboxyl group concentration of 20 eq/ton or less and intrinsic viscosity of 0.70-1.40 dl/g, (B) 0.1-5 pts.wt. of polycarbodiimide compound (B component) having softening temperature of 50°C or higher.

Description

  The present invention relates to a thermoplastic resin composition, and more particularly to a thermoplastic polyester resin composition for electric wire coating, which is formed by blending a thermoplastic polyester resin with a polycarbodiimide compound and is excellent in extrudability, heat deterioration resistance and wear resistance. .

  Conventionally, a material made of polyvinyl chloride resin (PVC resin) has been used as the wire covering material. As an electric wire covering material, PVC resin is excellent in that it has excellent insulating properties and is inexpensive. However, when the wire covering material made of PVC resin is incinerated after being discarded, there arises a problem of environmental pollution associated with waste processing such as generation of a gas containing chlorine. In recent transportation fields such as automobiles and trains, there has been a demand for lighter and thinner wire coverings with the reduction of the weight of the vehicle body and the space saving of wiring for energy saving. Therefore, an olefin-based material has been proposed as an electric wire coating material excellent in environment. (Refer to Patent Document 1) Olefinic materials are characterized by no problems of environmental pollution, high practicality, and low cost. However, mechanical strength and wear resistance in lightening and thinning the wire coating. The thing which is satisfied with is not obtained.

  On the other hand, as materials other than olefins, polyester resins which are engineering plastics polymers, and among them, thermoplastic polyester resins have been used. Thermoplastic polyester resin has excellent heat resistance, wear resistance, electrical properties, chemical resistance, moldability, low absorbency and excellent dimensional stability, so it can be used in a wide range of fields such as automobiles, electrical / electronics, insulating materials, and office automation. Used in the field. For example, it has been disclosed that since it has the above-described characteristics, there is a possibility that the weight and thickness of the wire coating can be reduced while maintaining wear resistance (see Patent Document 2). However, in recent years, further improvements in heat resistance and mechanical properties have been desired for the insulating materials of electric wires, and improvements are required. In view of this, high heat resistance has been improved by adding an epoxy group-containing additive to a thermoplastic polyester resin (see Reference 3), but sufficient heat deterioration characteristics have not been obtained. is the current situation. Moreover, what added the carbodiimide compound to the thermoplastic polyester resin as what further improved heat resistance is proposed. However, when the softening temperature of the carbodiimide compound is low, that is, when the molecular weight of the polycarbodiimide is low, the steric hindrance around the carbodiimide group is small, so that there is a problem that the heat resistance deteriorates. Furthermore, there is a problem in that polycarbodiimide having a low softening temperature adheres to the raw material charging inlet during the production of the composition, and industrially useful productivity cannot be obtained.

JP 2009-249390 A JP 2002-343141 A Japanese Patent Laid-Open No. 9-26385 JP 2007-211113 A

  Therefore, an object of the present invention is to provide a thermoplastic polyester resin composition for wire coating that has extrudability, heat deterioration resistance and wear resistance.

  As a result of repeated studies for the purpose of improving the heat deterioration property, the present inventors have found that polycarbodiimide, particularly polycarbodiimide having a high softening temperature, is effective in improving the heat deterioration resistance and productivity of this polyester, The present invention has been achieved.

  According to the present invention, (1) (A) 100 parts by weight of a thermoplastic polyester resin (component A) having a terminal carboxyl group concentration of 20 eq / ton or less and an intrinsic viscosity of 0.70 to 1.40 dl / g On the other hand, there is provided (B) a thermoplastic polyester resin composition for coating an electric wire containing 0.1 to 5 parts by weight of a polycarbodiimide compound (component B) having a softening temperature of 50 ° C. or higher.

  One of the preferred embodiments of the present invention is that (2) 100 parts by weight of component A is (C) phenolic antioxidant (component C) and / or (D) phosphorus antioxidant (component D) 0 It is a thermoplastic polyester resin composition of the said structure (1) containing 0.005-5 weight part.

  One of the preferred embodiments of the present invention is that (3) one or more kinds of heat selected from the group consisting of a polybutylene naphthalate resin (A-1 component) and a polybutylene terephthalate resin (A-2 component). It is a thermoplastic polyester resin composition having the above constitution (1) or (2), which is a plastic polyester resin.

  One preferred embodiment of the present invention is that the thermoplastic polyester resin composition of the above constitution (3) is characterized in that (4) the component A contains 50 wt% or more of a polybutylene naphthalate resin (component A-1). It is a thing.

  One of the preferred embodiments of the present invention is (5) the thermoplastic resin according to any one of the above constitutions (1) to (4), wherein the thickness of the wire coating is in the range of 0.01 mm to 0.5 mm. It is a polyester resin composition.

Hereinafter, the details of the present invention will be described.
(Component A: Thermoplastic polyester resin)
The component A in the present invention is a thermoplastic polyester resin. Examples of the thermoplastic polyester resin include polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polybutylene naphthalate resin, polycyclohexanedimethyl terephthalate resin, polytrimethylene terephthalate resin, and polytrimethylene naphthalate resin. Among them, polybutylene naphthalate resin and polybutylene terephthalate resin are preferably used, and the content of polybutylene naphthalate resin is preferably 50 wt% or more, more preferably 60 wt% or more.

  The thermoplastic polyester resin as component A of the present invention has a terminal carboxyl group concentration measured at 35 ° C. in benzyl alcohol of 20 eq / ton or less, preferably 18 eq / ton or less, more preferably 16 eq / ton or less. It is. When the terminal carboxyl group concentration is larger than 20 eq / ton, even if a polycarbodiimide compound is used in combination, the target heat aging resistance cannot be obtained.

  The thermoplastic polyester resin as component A of the present invention has an intrinsic viscosity of 0.70 to 1.40 dl / g, preferably 0.80 to 1.40 dl / g, measured at 35 ° C. in orthochlorophenol. Yes, 0.90 to 1.40 dl / g is more preferable. When the intrinsic viscosity is within this range, a thermoplastic polyester resin composition having good heat aging resistance and wear resistance can be obtained, and excellent processability during extrusion can be obtained.

(A-1 component: polybutylene naphthalate resin)
The polybutylene naphthalate resin (hereinafter sometimes abbreviated as “PBN”) which is the component A-1 of the present invention includes a dicarboxylic acid component mainly composed of naphthalene dicarboxylic acid and / or an ester-forming derivative of naphthalene dicarboxylic acid. It can be produced using a glycol component containing 1,4-butanediol as a main component.

  As the naphthalenedicarboxylic acid component, 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid are the main components, but other dicarboxylic acids can be used in combination as long as the characteristics are not impaired. Examples of other carboxylic acids include terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, diphenoxyethane-4,4′-dicarboxylic acid, diphenylsulfone-4,4′-dicarboxylic acid, diphenyl ether-4, Aromatic dicarboxylic acids such as 4'-dicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, succinic acid and oxalic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, etc. Two or more kinds may be used and can be arbitrarily selected according to the purpose. The amount of other carboxylic acid used is preferably 30 mol% or less, more preferably 20 mol% or less, based on the total acid component. As ester-forming derivatives of naphthalenedicarboxylic acid, dimethyl 2,6-naphthalenedicarboxylate and dimethyl 2,7-naphthalenedicarboxylate are the main components, but other dicarboxylic acid esters as long as the characteristics are not impaired. Formable derivatives can be used in combination. Examples of ester-forming derivatives of other dicarboxylic acids include terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid. Acids, lower dialkyl esters of aromatic dicarboxylic acids such as diphenyl ether-4,4'-dicarboxylic acid, lower dialkyl esters of alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, adipic acid, sebacic acid, succinic acid, oxalic acid, etc. The lower dialkyl ester of aliphatic dicarboxylic acid etc. are mentioned, These 1 type (s) or 2 or more types may be used, and it can select arbitrarily according to the objective. The amount of other dicarboxylic acid ester-forming derivatives used is preferably 30 mol% or less, more preferably 20 mol% or less, based on the total dicarboxylic acid ester-forming derivative component.

  Further, a tri- or higher functional carboxylic acid component such as a small amount of trimellitic acid may be used, and a small amount of an acid anhydride such as trimellitic anhydride may be used. Further, a small amount of hydroxycarboxylic acid such as lactic acid or glycolic acid or an alkyl ester thereof may be used and can be arbitrarily selected depending on the purpose.

  Although 1,4-butanediol is the main component of the glycol component, other glycol components can be used in combination as long as the characteristics are not impaired. Examples of other glycol components include ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, neopentylene glycol, hexamethylene glycol, decamethylene glycol, cyclohexane dimethanol, diethylene glycol, triethylene glycol, polyethylene glycol, One or more alkylene glycols such as (oxy) ethylene glycol, poly (oxy) tetramethylene glycol and poly (oxy) methylene glycol may be used, and can be arbitrarily selected according to the purpose. Furthermore, a small amount of a polyhydric alcohol component such as glycerin may be used. A small amount of an epoxy compound may be used. The amount of other glycol components used is preferably 30 mol% or less, more preferably 20 mol% or less, based on the total glycol components.

  The amount of the glycol component used is preferably 1.1 mol times or more and 1.4 mol times or less with respect to the dicarboxylic acid or the ester-forming derivative of dicarboxylic acid. When the amount of the glycol component used is less than 1.1 mole times, the esterification or transesterification reaction does not proceed sufficiently, which is not preferable. Further, when the amount exceeds 1.4 mol times or more, the reason is not clear, but the reaction rate is slow, and the amount of by-products such as tetrahydrofuran from the excessive glycol component is increased, which is not preferable.

  In the production of PBN, a titanium compound is used as a polymerization catalyst. As a titanium compound used as a polymerization catalyst, tetraalkyl titanate is preferable, and specifically, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetra-sec-butyl titanate, tetra-t-butyl. Titanate, tetra-n-hexyl titanate, tetracyclohexyl titanate, tetraphenyl titanate, tetrabenzyl titanate and the like may be mentioned, and these may be used as mixed titanates. Among these titanium compounds, tetra-n-propyl titanate, tetraisopropyl titanate, and tetra-n-butyl titanate are particularly preferable, and tetra-n-butyl titanate is most preferable. The addition amount of the titanium compound is preferably 10 ppm or more and 60 ppm or less, more preferably 15 ppm or more and 30 ppm or less as the titanium atom content in the produced PBN. When the titanium atom content in the produced PBN exceeds 60 ppm, the color tone and thermal stability of the thermoplastic polyester resin composition of the present invention are not preferred. On the other hand, when the titanium atom content is 10 ppm or less, good polymerization activity cannot be obtained, and PBN having a sufficiently high intrinsic viscosity cannot be obtained. The PBN of the present invention is obtained by esterifying or esterifying a dicarboxylic acid component mainly composed of naphthalenedicarboxylic acid and / or an ester-forming derivative thereof and a glycol component mainly composed of 1,4-butanediol in the presence of a titanium compound. It is preferably produced via an exchange reaction step and a subsequent polycondensation reaction step, but the temperature at the end of esterification or transesterification reaction is preferably in the range of 180 ° C. or more and 220 ° C. or less, More preferably, it is 180 ° C. or higher and 210 ° C. or lower. When the temperature at the end of the esterification reaction or transesterification reaction exceeds 220 ° C., the reaction rate increases, but it is not preferable because by-products such as tetrahydrofuran increase. On the other hand, if the temperature is less than 180 ° C., the reaction does not proceed. The reaction product (bisglycol ether and / or its low polymer) obtained by esterification or transesterification is reduced to 0.4 kPa (3 Torr) or less at a temperature not lower than the melting point of PBN and not higher than 270 ° C. Preference is given to polycondensation below. If the polycondensation reaction temperature exceeds 270 ° C., the reaction rate is rather lowered, and coloring is increased, which is not preferable.

(A-2 component: polybutylene terephthalate resin)
The polybutylene terephthalate resin (hereinafter sometimes abbreviated as “PBT”), which is the component A-2 of the present invention, is obtained by a polycondensation reaction from terephthalic acid or a derivative thereof and 1,4-butanediol or a derivative thereof. However, other dicarboxylic acids and glycols can be copolymerized as long as the object of the present invention is not impaired.

  Examples of copolymerizable dicarboxylic acids include isophthalic acid, 2-chloroterephthalic acid, 2,5-dichloroterephthalic acid, 2-methylterephthalic acid, 4,4-stilbene dicarboxylic acid, 4,4-biphenyldicarboxylic acid, and orthophthalic acid. Aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid, bisbenzoic acid, bis (p-carboxyphenyl) methane, anthracene dicarboxylic acid, 4,4-diphenyl ether dicarboxylic acid, 4,4-diphenoxyethanedicarboxylic acid, Mention may be made of aliphatic and alicyclic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid. These copolymerizable dicarboxylic acids can be used alone or in admixture of two or more.

  Examples of copolymerizable glycols include 1,2-propylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, trans- or cis-2,2,4,4-tetramethyl. -1,3-cyclobutanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, decamethylene glycol, cyclohexanediol, p -Xylene diol, bisphenol A, etc. can be mentioned. If the amount is even smaller, one or more long-chain diols having a molecular weight of 400 to 6,000, that is, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, and the like may be copolymerized. These copolymerizable glycols can be used alone or in combination of two or more.

  The PBT of the present invention can be branched by introducing a small amount of a branching agent. Although there is no restriction | limiting in the kind of branching agent, A trimesic acid, a trimellitic acid, a trimethylol ethane, a trimethylol propane, a pentaerythritol, etc. are mentioned.

  The terminal group structure of the obtained PBT is not particularly limited as long as the terminal carboxyl group concentration is in the range of 20 eq / ton or less. Other than the case where the ratio of hydroxyl groups to carboxyl groups in the terminal groups is approximately the same amount. , It may be a case where the ratio of one is large. Moreover, those terminal groups may be sealed by reacting a compound having reactivity with such terminal groups.

  About the manufacturing method of PBT of this invention, according to a conventional method, the dicarboxylic acid component and the said diol component are superposed | polymerized in the presence of the polycondensation catalyst containing titanium, germanium, antimony, etc., and water byproduced. Alternatively, the lower alcohol is discharged out of the system. For example, germanium-based polymerization catalysts include germanium oxides, hydroxides, halides, alcoholates, phenolates, and the like. More specifically, germanium oxide, germanium hydroxide, germanium tetrachloride, tetramethoxygermanium, etc. Can be illustrated.

  Further, in the present invention, compounds such as manganese, zinc, calcium, magnesium, etc., which are used in a transesterification reaction that is a prior stage of a conventionally known polycondensation, can be used in combination, and phosphoric acid or phosphorous after completion of the transesterification reaction. Such a catalyst can be deactivated and polycondensed with an acid compound or the like.

(B component: polycarbodiimide compound)
The polycarbodiimide compound used as the component B in the present invention is a (co) polymer using a polyvalent isocyanate compound. Specific examples of the polyvalent isocyanate include, for example, hexamethylene diisocyanate, xylene diisocyanate, cyclohexane diisocyanate, pyridine diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, p-phenylene. Diisocyanate, m-phenylene diisocyanate, 1,5-naphthylene diisocyanate and the like can be mentioned. Of these, cyclohexane diisocyanate and 2,4-tolylene diisocyanate are preferably used.

  Examples of the polycarbodiimide compound of the component B include Carbodilite HMV-8CA and Carbodilite LA-1 manufactured by Nisshinbo Industries, Inc. and Stabuzol P manufactured by Rhein Chemie.

  The content of the polycarbodiimide compound is 0.1 to 5 parts by weight, preferably 0.3 to 4 parts by weight, more preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the thermoplastic polyester resin. . When the content is less than 0.1 parts by weight, the effect of improving heat aging resistance and wear resistance is not sufficient, and when it exceeds 5 parts by weight, the workability during extrusion is remarkably deteriorated due to an increase in melt viscosity. Can not be obtained.

  The softening temperature of the polycarbodiimide compound is 50 ° C. or higher, preferably 60 ° C. or higher, more preferably 70 ° C. or higher. If the softening temperature is less than 50 ° C., the material is melted under a raw material supply hopper at the time of extrusion, causing a chute up and making extrusion difficult. Since a polycarbodiimide compound having a softening temperature higher than 120 ° C. is difficult to produce, it has no industrial utility. For this reason, the upper limit of the softening temperature of the polycarbodiimide compound is substantially 120 ° C.

(C component: hindered phenol antioxidant)
The C component of the present invention is a hindered phenol acid value inhibitor. The main purpose of blending such a hindered phenolic antioxidant is to improve the thermal stability and heat deterioration resistance during molding of the thermoplastic polyester resin composition. Examples of such hindered phenol-based antioxidants include α-tocopherol, butylhydroxytoluene, sinapir alcohol, vitamin E, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2-tert-butyl-6- (3′-tert-butyl-5′-methyl-2′-hydroxybenzyl) -4-methylphenyl acrylate, 2,6-di-tert-butyl-4- (N, N -Dimethylaminomethyl) phenol, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl ester, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis ( 4-ethyl-6-tert-butylphenol), 4,4′-methylenebis ( , 6-di-tert-butylphenol), 2,2′-methylenebis (4-methyl-6-cyclohexylphenol), 2,2′-dimethylene-bis (6-α-methyl-benzyl-p-cresol) 2, 2′-ethylidene-bis (4,6-di-tert-butylphenol), 2,2′-butylidene-bis (4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6) -Tert-butylphenol), triethylene glycol-N-bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, 1,6-hexanediol bis [3- (3,5- Di-tert-butyl-4-hydroxyphenyl) propionate], bis [2-tert-butyl-4-methyl 6- (3-tert Butyl-5-methyl-2-hydroxybenzyl) phenyl] terephthalate, 3,9-bis {2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1, -Dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, 4,4'-thiobis (6-tert-butyl-m-cresol), 4,4'-thiobis (3- Methyl-6-tert-butylphenol), 2,2′-thiobis (4-methyl-6-tert-butylphenol), bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, 4,4 ′ -Di-thiobis (2,6-di-tert-butylphenol), 4,4'-tri-thiobis (2,6-di-tert-butylphenol), 2,2-thio Ethylenebis- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis (n-octylthio) -6- (4-hydroxy-3,5-di-tert -Butylanilino) -1,3,5-triazine, N, N'-hexamethylenebis- (3,5-di-tert-butyl-4-hydroxyhydrocinnamide), N, N'-bis [3- ( 3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5- Trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-tert-butyl-4-hydroxyphenyl) Isocyanurate, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate 1,3,5-tris2 [3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl isocyanurate and tetrakis [methylene-3- (3,5-di-tert- Butyl-4-hydroxyphenyl) propionate] methane and the like. Among these, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (CIBA SPECILITY CHEMICALS: Irganox 1076 (trade name)) is preferable as a typical commercial product. All of the above-mentioned hindered phenolic antioxidants are easily available, and these can be used alone or in combination of two or more.

(D component: Phosphorous antioxidant)
The D component of the present invention is a phosphorus antioxidant. The main purpose of blending such a phosphorus-based antioxidant is to improve the thermal stability during molding of the resin composition and to improve the heat aging resistance of the thermoplastic polyester resin composition. Examples of such phosphorus antioxidants include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid and esters thereof, and tertiary phosphine.

  Examples of the phosphite compound include triphenyl phosphite, tris (nonylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl Monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, tris (diethylphenyl) phos Phyto, tris (di-iso-propylphenyl) phosphite, tris (di-n-butylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite Ite, tris (2,6-di-tert-butylphenyl) phosphite, distearyl pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6 -Di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-ethylphenyl) pentaerythritol diphosphite, bis {2,4-bis (1 -Methyl-1-phenylethyl) phenyl} pentaerythritol diphosphite, phenylbisphenol A pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, and dicyclohexyl pentaerythritol diphosphite. . Further, as other phosphite compounds, those which react with dihydric phenols and have a cyclic structure can be used. For example, 2,2′-methylenebis (4,6-di-tert-butylphenyl) (2,4-di-tert-butylphenyl) phosphite, 2,2′-methylenebis (4,6-di-tert- Examples include butylphenyl) (2-tert-butyl-4-methylphenyl) phosphite, 2,2′-methylenebis (4-methyl-6-tert-butylphenyl) octyl phosphite, and the like.

  Examples of the phosphate compound include tributyl phosphate, trimethyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresyl phosphate, diphenyl monoorxenyl phosphate, tributoxyethyl phosphate, dibutyl phosphate, dioctyl phosphate, And diisopropyl phosphate are exemplified, and triphenyl phosphate and trimethyl phosphate are preferable.

  Examples of the phosphonite compound include tetrakis (2,4-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3′-biphenylenedi. Phosphonite, tetrakis (2,4-di-tert-butylphenyl) -3,3′-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite Tetrakis (2,6-di-tert-butylphenyl) -4,3′-biphenylene diphosphonite, tetrakis (2,6-di-tert-butylphenyl) -3,3′-biphenylene diphosphonite, bis (2,4-di-tert-butylphenyl) -4-phenyl-phenylphosphonite, bis (2,4-di tert-butylphenyl) -3-phenyl-phenylphosphonite, bis (2,6-di-n-butylphenyl) -3-phenyl-phenylphosphonite, bis (2,6-di-tert-butylphenyl)- 4-phenyl-phenylphosphonite, bis (2,6-di-tert-butylphenyl) -3-phenyl-phenylphosphonite, and the like, and tetrakis (di-tert-butylphenyl) -biphenylenediphosphonite, Bis (di-tert-butylphenyl) -phenyl-phenylphosphonite is preferred, tetrakis (2,4-di-tert-butylphenyl) -biphenylenediphosphonite, and bis (2,4-di-tert-butylphenyl) ) -Phenyl-phenylphosphonite is more preferred. Such a phosphonite compound is preferable because it can be used in combination with a phosphite compound having an aryl group in which two or more alkyl groups are substituted.

  Examples of the phosphonate compound include dimethyl benzenephosphonate, diethyl benzenephosphonate, and dipropyl benzenephosphonate.

  Tertiary phosphine includes triethylphosphine, tripropylphosphine, tributylphosphine, trioctylphosphine, triamylphosphine, dimethylphenylphosphine, dibutylphenylphosphine, diphenylmethylphosphine, diphenyloctylphosphine, triphenylphosphine, tri-p-tolyl. Examples include phosphine, trinaphthylphosphine, and diphenylbenzylphosphine. A particularly preferred tertiary phosphine is triphenylphosphine.

The phosphorus stabilizer can be used not only in one kind but also in a mixture of two or more kinds. Among the phosphorus antioxidants, phosphite compounds or phosphonite compounds are preferable.
The content of the hindered phenolic antioxidant as component C and the phosphorus antioxidant as component D is 0.005 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic polyester resin (component A). More preferably, it is 0.008-3 weight part, More preferably, it is 0.01-1 weight part. If the content is less than 0.005 parts by weight, there is no effect of improving the heat stability and heat aging resistance, and if it exceeds 5 parts by weight, the heat stability and heat aging resistance are deteriorated.

(Other additives)
In the thermoplastic polyester resin composition of the present invention, other thermoplastic resins are blended within a range that does not impair the effects of the invention, and if necessary, a plasticizer, an inorganic filler, a flame retardant, a vulcanization (crosslinking) agent, Pigments, light stabilizers, antistatic agents, antiblocking agents, lubricants, dispersants, fluidity improvers, mold release agents, nucleating agents, neutralizing agents and the like can be added. Examples of other thermoplastic resins include copolymers mainly composed of ethylene, (meth) acrylic acid ester, styrene and the like. The amount of these additives and thermoplastic resin is usually 0.01 to 50 parts by weight with respect to 100 parts by weight of the thermoplastic polyester resin.

(Insulated wire manufacturing method)
Next, an embodiment of a method for manufacturing an insulated wire according to the present invention will be described.
A known method can be used for the method of manufacturing the insulated wire. For example, the thermoplastic polyester resin composition is melt-kneaded using a normal extrusion line, and the conductor is mainly composed of the thermoplastic polyester resin. It can be made by extruding the composition. For melt kneading, for example, a batch kneader or a twin screw extruder is used. For example, a twin screw extruder is used for the extrusion line, but other than the twin screw may be used. Resin having an extrusion temperature of 290 ° C. to 310 ° C. is extruded by controlling the temperature of the head portion of the twin screw extruder to a predetermined temperature within the range of 290 ° C. to 310 ° C. by this twin screw extruder. The conductor is coated with the composition.

  As the conductor, a copper wire may be used as a single wire, or may be used as a plurality of stranded wires or knitted wires. The copper wire may be subjected to hot dipping or tin plating by electrolysis. In addition, the insulated wire only needs to cover the outer periphery of the conductor with the resin composition. As another form, the outer periphery of the conductor is covered with the resin composition, and the outer periphery is covered with the sheath layer. Alternatively, there is a structure in which a plurality of conductors coated with a thermoplastic polyester resin composition are twisted and the outer periphery thereof is covered with a sheath layer.

  Moreover, it is preferable to make the extrusion temperature of the said resin composition into the range of 280 degreeC-310 degreeC. If the temperature exceeds 310 ° C., the resin composition may be partially decomposed, or the molecular weight of the thermoplastic resin may be reduced, causing hump-like foreign matter or an abnormality in the outer diameter of the wire. If the temperature is lower than 280 ° C., the thermoplastic resin is not completely melted, which may lead to a cause of poor appearance or may be impossible to extrude.

  In addition, the thickness of the wire coating made of the resin composition covering the conductor is preferably in the range of 0.01 mm to 0.5 mm in order to reduce the weight and thickness of the wire, and is 0.02 mm to 0 mm. The range of 4 mm is more preferable. If the thickness of the insulator is less than 0.01 mm, it is difficult to maintain the wear resistance, and if it exceeds 0.5 mm, the winding diameter of the electric wire becomes large and handling becomes difficult. The conductor diameter is preferably in the range of 0.1 mm to 2 mm. The cross-sectional shape of the conductor is not limited to a round shape, and may be a rectangular shape obtained by slitting a plate-like copper plate or rolling a round wire.

  The wire coating of the above-described embodiment is used for a resin composition mainly composed of a thermoplastic resin having excellent wear resistance and tensile elongation characteristics. Therefore, even if the weight is reduced and the thickness is reduced, the mechanical strength and heat resistance are increased. An electric wire covering excellent in properties can be obtained and is suitable for electric wires for vehicles such as automobiles and trains.

  Since the thermoplastic polyester resin of the present invention is excellent in extrudability, heat deterioration resistance, and wear resistance, it is suitable as a resin for covering an electric wire, and its effect is extremely large.

It is explanatory drawing which shows the method of an abrasion resistance test.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Modes for carrying out the present invention will be described below. However, the embodiments are exemplarily shown, and various modifications can be made without departing from the technical idea of the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these. In each description, “parts” indicates mass parts, and “%” indicates mass%. Various physical properties were measured by the following methods.

1. Measurement of Resin Properties (1) Intrinsic Viscosity (IV) Measurement 0.6 g of resin was dissolved in 50 ml of orthochlorophenol by heating and then cooled to room temperature. The viscosity of the resulting resin solution was measured using an Ostwald type viscosity tube. The measurement was performed at a temperature of 35 ° C. The intrinsic viscosity (IV) of the resin was calculated from the obtained solution viscosity data.

(2) Terminal carboxyl group concentration measurement 0.4 g of resin was dissolved in 100 ml of benzyl alcohol at room temperature, and the obtained resin solution was 0.1N-NaOH using an automatic titrator GT-100 type (manufactured by Mitsubishi Chemical). Titration value, equivalent concentration of terminal carboxyl groups per 1 × 10 ⁶ g.

(3) Softening temperature measurement Using a differential scanning calorimeter (DSC), the softening temperature was measured under a nitrogen atmosphere at a heating rate of 20 ° C / min.

(4) Extrudability The resin composition was melt kneaded and pelletized under the following conditions. When it was carried out, the additive was welded in the vicinity of the feeding part of the extrusion, and the one that did not shoot up was marked as ◯ (good extrudability), and the one that could not be shooted up and pushed out was marked as x (extrusion failure).

(5) Tensile elongation The copper wire is extracted from the following wire sample to produce a tube-shaped test piece (outer diameter 1.9 mm, inner diameter 1.3 mm, length 150 mm). In the tester, the test piece after 96 hours of treatment at 150 ° C. was conditioned and subjected to a tensile elongation test. The tensile elongation test was carried out according to JIS C 3005 with the test piece at a tensile speed of 200 mm / min. Those having a tensile elongation of 200% or more were evaluated as ◯ (passed), and those other than that were evaluated as x (failed). The tensile elongation rate is calculated by the following formula.
Tensile elongation (%) = [(Sample length after tensile test) − (Test length before tensile test)] / (Sample length before tensile test) × 100

(6) Abrasion resistance Abrasion resistance test was performed on an insulated wire (insulator coating thickness: 0.3 mm, length: about 60 cm) using a wear tester in a room temperature atmosphere. . In this abrasion resistance test, as shown in FIG. 1, the 90 ° sharp edge 4 of the abrasion tester is applied to the electric wire 1 from above, and a load of 2 pounds (907 g) is applied to the electric wire 1 from the 90 ° sharp edge 4. Pressed. With this load applied, the electric wire 1 is reciprocated in the length direction, and the reciprocating operation is performed until the insulator 3 of the electric wire 1 is worn and the 90 ° sharp edge 4 contacts the conductor 2 and is short-circuited. The number of cycles was measured. A power source 5 and a lamp for detecting a short circuit are connected between the conductor 2 of the electric wire 1 and the 90 ° sharp edge 4. Indicates the number of reciprocating operations (cycles) until short circuit occurs. The number of times needs to be 150 times or more.

2. Production of PBN <Production Example 1: Production of PBN (IV = 1.1) by Solid Phase Polymerization>
2,5-naphthalenedicarboxylic acid dimethyl ester 315.0 parts, 1.4-butanediol 200. 0 parts, tetra-n-butyl titanate 0.062 parts were put in a transesterification reaction vessel, and the transesterification reaction vessel was 210 ° C. The ester exchange reaction was carried out for 150 minutes while raising the temperature. Subsequently, the obtained reaction product was transferred to a polycondensation reaction tank to start a polycondensation reaction. In the polycondensation reaction, the pressure in the polycondensation reaction layer is gradually reduced from normal pressure to 0.13 kPa (1 Torr) or less over 40 minutes, and the temperature is simultaneously raised to a predetermined reaction temperature of 260 ° C. The polycondensation reaction was carried out for 140 minutes while maintaining the state of 0 ° C. and the pressure of 0.13 kPa (1 Torr). When 140 minutes had elapsed, the polycondensation reaction was completed, PBN was extracted in a strand shape, and cut into chips using a cutter while cooling with water. Next, the obtained PBN was subjected to solid phase polymerization for 8 hours under the conditions of a temperature of 213 ° C. and a pressure of 0.13 kPa (1 Torr) or less. The obtained PBN (PBN-1) was measured for intrinsic viscosity and terminal carboxyl group concentration, and the results are shown in the table.

<Production Example 2: Production of PBN (IV = 1.4) by Solid State Polymerization>
A transesterification reaction and a polycondensation reaction were carried out in the same manner as in Production Example 1, and the obtained PBN was subjected to solid phase polymerization under the conditions of 213 ° C. and a pressure of 0.13 kPa (1 Torr) or less for 12 hours. The obtained PBN (PBN-2) was measured for intrinsic viscosity and terminal carboxyl group concentration, and the results are shown in the table.

<Production Example 3: Production of PBN (IV = 0.8) by Solid State Polymerization>
A transesterification reaction and a polycondensation reaction were carried out in the same manner as in Production Example 1, and the obtained PBN was subjected to solid phase polymerization at 213 ° C. under a pressure of 0.13 kPa (1 Torr) or less for 4 hours. The obtained PBN (PBN-3) was measured for intrinsic viscosity and terminal carboxyl group concentration, and the results are shown in the table.

<Production Example 4: Production of PBN (IV = 1.5) by Solid State Polymerization>
A transesterification reaction and a polycondensation reaction were carried out in the same manner as in Production Example 1, and the obtained PBN was subjected to solid phase polymerization at 213 ° C. under a pressure of 0.13 kPa (1 Torr) or less for 15 hours. The obtained PBN (PBN-4) was measured for intrinsic viscosity and terminal carboxyl group concentration, and the results are shown in the table.

<Production Example 5: Production of PBN (IV = 0.5) by melt polymerization>
Except that solid phase polymerization was not performed, a transesterification reaction and a polycondensation reaction were performed in the same manner as in Production Example 1 to obtain PBN (PBN-5). The obtained PBN was measured for intrinsic viscosity and terminal carboxyl group concentration, and the results are shown in the table.

<Production Example 6: Production of PBN (IV = 0.9) by melt polymerization>
Except for changing the polycondensation reaction time from 140 minutes to 170 minutes, a transesterification reaction and a polycondensation reaction were carried out in the same manner as in Production Example 4 to obtain PBN (PBN-6). The obtained PBN was measured for intrinsic viscosity and terminal carbodixyl group concentration. The results are shown in the table.

[Example 1-9, Comparative Example 1-8]
Examples will be described below.
The composition is mixed with the composition shown in Table 1, and melt kneaded at 280 ° C. to 290 ° C. using a twin screw extruder, and the resulting kneaded product is pulverized to a rice grain size and pelletized, and then a hot air dryer At 140 ° C. for 6 hours. Next, the resin composition obtained in the above step was extruded with a coating thickness of 0.3 mm around a tin-plated annealed copper wire having a diameter of 1.3 mm. For extrusion molding, dies and nipples with diameters of 4.2 mm and 2.0 mm are used, the extrusion speed is 5 m / min, the extrusion temperature is 270 ° C. to 290 ° C. for the cylinder part, and the head part is 280 to 290 ° C. It was. Characteristic evaluation was implemented by said method about the produced thermoplastic polyester resin, a thermoplastic polyester resin composition, and a covered electric wire. The results are shown in Tables 1 and 2.

In addition, the detail of each used component is as follows.
(Component A: Thermoplastic polyester resin)
(A-1 component: polybutylene naphthalate resin)
PBN-1: Polybutylene naphthalate resin (Production Example 1)
PBN-2: Polybutylene naphthalate resin (Production Example 2)
PBN-3: Polybutylene naphthalate resin (Production Example 3)
PBN-4: Polybutylene naphthalate resin (Production Example 4)
PBN-5: Polybutylene naphthalate resin (Production Example 5)
PBN-6: Polybutylene naphthalate resin (Production Example 6)
(A-2 component: polybutylene terephthalate resin)
PBT-1: Polyplastics Co., Ltd. Product name: 300FP (IV = 0.69 dl / g terminal carboxyl group concentration 20 eq / ton)
PBT-2: manufactured by Polyplastics Co., Ltd. Product name: 700FP (IV = 1.14 dl / g terminal carboxyl group concentration 7 eq / ton)
(B component: polycarbodiimide compound)
B-1: Nisshinbo Co., Ltd., trade name: HMV-8CA (softening temperature: 71 ° C.)
B-2: manufactured by Rhein Chemie Co., Ltd., trade name: Stavacsol P (softening temperature: 65 ° C.)
B-3: manufactured by Rhein Chemie Co., Ltd., trade name: Stavacsol I (softening temperature: 40 ° C.)
(C component: hindered phenol antioxidant)
C-1: IRGANOX1076 manufactured by Ciba Specialty Chemicals Co., Ltd.
(D component: Phosphorous antioxidant)
D-1: ADK STAB PEP-24G manufactured by Asahi Denka Kogyo Co., Ltd.

  In Table 1, Examples 1 to 9 in which a polycarbodiimide compound having a softening temperature in a specific range was blended with a thermoplastic polyester resin having a specific range of terminal carboxyl group concentration and intrinsic viscosity showed excellent extrudability, and It can be seen that the resin composition for coating electric wires has a high level of tensile elongation and wear resistance, is industrially useful, and has both excellent heat aging resistance and wear resistance. In particular, Example 5 has high wear resistance and excellent characteristics. In Table 2, since Comparative Example 1 used PBN having an intrinsic viscosity outside the range of the present invention, torque was exceeded during extrusion, and no wire coating was obtained. Since the comparative example 2 used the thermoplastic polyester resin whose terminal carboxyl group density | concentration is outside the range of this invention, its tensile elongation rate is inferior compared with Example 1. FIG. Comparative Example 3 has lower abrasion resistance than Comparative Example 2 because both the terminal carboxyl group concentration and the intrinsic viscosity are outside the scope of the present invention. Since Comparative Example 4 does not contain a polycarbodiimide compound, the tensile elongation and the wear resistance are greatly inferior to those of Example 1. Since Comparative Example 5 uses a monocarbodiimide compound having a softening temperature lower than the range of the present invention, shoot-up occurred at the time of extrusion, and no wire coating was obtained. In Comparative Examples 6 and 7, since the polycarbodiimide compound was blended beyond the range of the present invention, the melt viscosity was high, the extrusion process was difficult, a uniform wire coating was not obtained, and sufficient tensile elongation was not obtained. Since the comparative example 8 used the thermoplastic polyester resin of intrinsic viscosity lower than the range of this invention, tensile elongation is inferior compared with Example 7 and 8. FIG.

1. 1. Insulated wire Conductor 3. 4. Insulator 4. 90 ° sharp edge Power supply

Claims (5)

  (A) With respect to 100 parts by weight of a thermoplastic polyester resin (component A) having a terminal carboxyl group concentration of 20 eq / ton or less and an intrinsic viscosity of 0.70 to 1.40 dl / g, (B) the softening temperature is A thermoplastic polyester resin composition for covering electric wires, containing 0.1 to 5 parts by weight of a polycarbodiimide compound (component B) having a temperature of 50 ° C or higher.   The content of (C) hindered phenolic antioxidant (C component) and / or (D) phosphorus antioxidant (D component) is 0.005 to 5 parts by weight with respect to 100 parts by weight of component A. The thermoplastic polyester resin composition described in 1.   The A component is one or more thermoplastic polyester resins selected from the group consisting of a polybutylene naphthalate resin (A-1 component) and a polybutylene terephthalate resin (A-2 component). 2. The thermoplastic polyester resin composition according to 2.   The thermoplastic polyester resin composition according to claim 3, wherein the component A contains 50 wt% or more of a polybutylene naphthalate resin (component A-1).   The thermoplastic polyester resin composition according to any one of claims 1 to 4, wherein the thickness of the wire coating is in the range of 0.01 mm to 0.5 mm.

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